From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E981DC43217 for ; Mon, 3 Oct 2022 22:29:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229823AbiJCW3E (ORCPT ); Mon, 3 Oct 2022 18:29:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229678AbiJCW2w (ORCPT ); Mon, 3 Oct 2022 18:28:52 -0400 Received: from mail-pg1-x530.google.com (mail-pg1-x530.google.com [IPv6:2607:f8b0:4864:20::530]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 269A013FB0 for ; Mon, 3 Oct 2022 15:28:49 -0700 (PDT) Received: by mail-pg1-x530.google.com with SMTP id j71so4711369pge.2 for ; Mon, 03 Oct 2022 15:28:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date; bh=+wnywtAQvf5k8l6QfV3gcIXHNKvc8BplZWtX49oDhHc=; b=H/p7lvN0ivhZ/ZUi0b1ymdJCdg09uvOJ+n08JqQMJX34z0HB4NQM60kOzdXXVDMjYr xvwOo7FvBT/LWZkr+sqMomIG4ecCsdqBQOKTMQoFnDScjMd/yg5qd907sZvhultWzURx SyYeNSNrz5ok6t2vENsv7nnoAKrZbbweIbd0I= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date; bh=+wnywtAQvf5k8l6QfV3gcIXHNKvc8BplZWtX49oDhHc=; b=iYRwolqocGTP7Dim6mTsUO1ROlS+FRCVLbvJQR85sDleu+H26BBowj36Lka+4qVlS0 Z5fPjxmq2NecXrfU3HwPxIhCilqQ1ktpay2jUoEnCaoGw0j3fWP5FDYWUsHJwZZmgX62 OCp6hSS3o4J79cm93Vqlk3dCfEAyqPDDp6EaSlJJYHMABGCc7X5ZIkuhHxI3vDvsCR9E CSLpjkIkelQYsQ31YNly7AkpvpYJwISFwbqtX6pF+UrOJKOM4w5XjmpdPlJ+MZw462Wx wWh9YqTLPyx/0axxekHAFNydJOtwWJk7mxoinMYeOfsfY4u9EObOl1C1wVyW/PE/2z1X A71w== X-Gm-Message-State: ACrzQf2oRGRBLgeDrMjgzeNn5XDhFj/WXQW+KVWEh8kPaIa61a1V2BUv WYSubrTVTAR/LS5VWI2dRRuP2g== X-Google-Smtp-Source: AMsMyM7u4PcmOvVI/uNaqNfnpw33KHljDf3vY+Qdun5s8TjCJBcY3DqmJr+5IYdkQEWD6PqNwIPWug== X-Received: by 2002:a63:1141:0:b0:454:ae43:14e7 with SMTP id 1-20020a631141000000b00454ae4314e7mr788927pgr.527.1664836128678; Mon, 03 Oct 2022 15:28:48 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id 129-20020a621787000000b0053e20a0333fsm8096309pfx.93.2022.10.03.15.28.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Oct 2022 15:28:48 -0700 (PDT) Date: Mon, 3 Oct 2022 15:28:47 -0700 From: Kees Cook To: Rick Edgecombe Cc: x86@kernel.org, "H . Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H . J . Lu" , Jann Horn , Jonathan Corbet , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V . Shankar" , Weijiang Yang , "Kirill A . Shutemov" , joao.moreira@intel.com, John Allen , kcc@google.com, eranian@google.com, rppt@kernel.org, jamorris@linux.microsoft.com, dethoma@microsoft.com Subject: Re: [PATCH v2 29/39] x86/cet/shstk: Support wrss for userspace Message-ID: <202210031525.78F3FA8@keescook> References: <20220929222936.14584-1-rick.p.edgecombe@intel.com> <20220929222936.14584-30-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220929222936.14584-30-rick.p.edgecombe@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Thu, Sep 29, 2022 at 03:29:26PM -0700, Rick Edgecombe wrote: > For the current shadow stack implementation, shadow stacks contents easily > be arbitrarily provisioned with data. I can't parse this sentence. > This property helps apps protect > themselves better, but also restricts any potential apps that may want to > do exotic things at the expense of a little security. Is anything using this right now? Wouldn't thing be safer without WRSS? (Why can't we skip this patch?) -- Kees Cook